The goal of the project is to evaluate the effectiveness of dentists and dental hygienists advising their patients to quit smoking cigarettes and/or using smokeless tobacco. Adult patients (age 18-65) will be identified as smokers or chew/snuff users in the context of their regularly scheduled dental hygiene visit. The study compares two levels of intervention--brief and extended--to usual care for smokers, and an extended intervention with usual care for smokeless users. The study involves recruitment and randomization of 60 independent practice solo practitioner dental offices which employ a dental hygienist at least half time. Dental practices in three Oregon counties will be blocked on location, size of practice, and dentist's age, and then randomized. The study will enroll 5760 smokers and 1037 smokeless users over a 9-month enrollment period. Patients are identified as tobacco users via a brief health survey. The study has four phases: Phase One involves development and testing of written materials and videos for both smoking and smokeless, recruitment of dental practices and pilot testing procedures. Phase Two involves training dentists, hygienists and staff to carry out enrollment and intervention, and implementation of the intervention. Enrollment and intervention will be phased in over 6 months and continue for 9 months. Phase Three involves follow-up assessment of dental patients' tobacco use 3 and 12 months post-enrollment. Non-respondents to the mailed surveys will be assessed by phone interview. A subset of 20% of the patients will receive a brief phone interview to monitor provider adherence. Phase Four involves completing analysis of outcome data, cost analysis comparing the cost per quit in the three groups and assessing life years saved for smokers, and training Usual Care dental practice staff in the intervention.